Meiotrichum was originally placed in Polytrichadelphus (Müller Hal.) Mitten (not present in our area) because of the fastigiate habit and sparsely hairy calyptra. All Polytrichadelphus species have lamellae which are crenulate in profile, the marginal cells smooth and flask-shaped in section, a dorsiventral capsule with two sharp angles, and multiple stomata dispersed over the exothecium, none of which occurs in Meiotrichum.